Stoppers
Stoppers, also known as bungs, are used to give an airtight seal to laboratory flasks and test tubes by fitting tightly inside the neck of the container and preventing material from spilling. Stoppers can be made of glass, cork, rubber, or silicone. They are typically designed with a conical shape, but straight, flanged, and tapered options are also available.
Stoppers are the preferred choice for many applications requiring a tighter seal or a greater degree of chemical resistance. They also provide a good seal when a solution needs to be shaken or mixed without spilling. Stoppers are generally cylindrical in shape and have a tapered bottom end. They may be marked with a stopper number or size on the top and bottom diameters of the stopper. Sizing can vary among manufacturers.
Stoppers are available in a solid design or with holes known as positions placed in the top. Positions allow easy access to the material contained in the sealed vessel by pipettes, tubing, or other equipment without full removal of the stopper.
What Types of Stoppers Are Available?
• Turnover stoppers have external serrations to create an excellent internal seal combined with a flexible turnover sleeve that folds down over the container’s neck to create a double seal
• Serum bottle or vial stoppers have two or three legs with external serrations or straight sides and a flanged top to create an airtight seal
• Straight bromobutyl plug-type stoppers provide a maximum seal for vials and serum bottles with a straight-wall glass finish
• Ultra-pure, straight bromobutyl plug-type stoppers provide high chemical purity and low gas permeability. They offer excellent performance during freeze drying processes such as lyophilization, where stoppers must remain stable during transfer and sublimination phases
• Silicone recessed septa stoppers are non-toxic and have external serrations to create an effective internal seal
Ace Glass, Inc. 29/42 Bent Vertical Hose Barb Vacuum Trap Stopper
29/42 Bent Vertical Hose Barb Vacuum Trap Stopper
Ace Glass, Inc. 50/50 Bent Vertical Hose Barb Vacuum Trap Stopper
50/50 Bent Vertical Hose Barb Vacuum Trap Stopper
Ace Glass, Inc. 500mL gas wash stopper only, porosity A
500mL gas wash stopper with porosity A (145-174micron) fritted disc.
Ace Glass, Inc. 125mL gas wash stopper only, porosity C
125mL gas washing stopper with porosity C (25-50 micron) 25mm fritted disc diameter, and 40/35 joint. Inlet/outlet arms are 8mm O.D.
West Pharmaceutical Services Inc WEST PHARMACEUTICAL SERVICES INC
NC3956232 20MM 4432/50 GRAY 8000PCS
Electron Microscopy Sciences Vacule Lyophylization Stoppers, 2 Prong
Heavy wall construction, designed for lyophilization and freeze-drying. Manufactured from Wheaton 33 low extractable borosilicate glass (meets ASTM Type I Class and USP Type I Standards). Accessory for 4 ml Vacule Vials.
Chemglass Life Sciences Rubber Stopper, #0, One Hole, Black
Rubber Stopper, #0, One Hole, Black. These stoppers are suitable for practically all general laboratory uses. Composition ensures resiliency and pliability over a long period and withstands laboratory conditions without hardening. The dimensions are in accordance with specifications established by the N.B.S. and are low in free sulfur (1/2%). Autoclavable at 250F for 30 minutes under water or steam conditions only (not dry heat). End user must test for their specific application. Diameter: Top (17mm), Bottom (13mm). Length: (25mm). Diameter of hole: (3mm).
Chemglass Life Sciences Rubber Stopper, #10-1/2, Two Holes, Black
Rubber Stopper, #10-1/2, Two Holes, Black. Similar to CG-3026 and CG-3027 except with two holes. These stoppers are suitable for practically all general laboratory uses. Composition ensures resiliency and pliability over a long period and withstands laboratory conditions without hardening. The dimensions are in accordance with specifications established by the N.B.S. and are low in free sulfur (1/2%). Autoclavable at 250F for 30 minutes under water or steam conditions only (not dry heat). End user must test for their specific application. Diameter: Top (53mm), Bottom (45mm). Length: (25mm). Diameter of holes: (5mm).
Cole-Parmer Solid Color-Coded Silicone Stoppers, Standard Size 8, Green; 10/Bag
Silicone bubbles make these stoppers lightweight—they float on water. Withstand temperatures from –76 to 392°>F (–60 to 200°>C). Stoppers are available in 14 color-coded sizes, given in both standard and Japanese size numbers. Softness and flexibility allow stoppers to fit a range of holes. Easily make openings for glassware fit your exact specifications with the optional cork borer set. 2 bg/cs.*
Alkali Scientific CellPro™ 24-Well, Silicone Sealing Mats, 50/pk, Sterile
CellPro™ 24 Well, Silicone Sealing Mats seals 24 wells at a time for minimal evaporation / sample loss, guaranteeing sample integrity, high quality data and uninterrupted workflow. They are useful in PCR, and HTS sample storage and are available in multiple sizes. For a perfect, leakproof seal with most popular plates.